Jetty helper to manually load web-fragment.xml from JARs and class folders on the classpath.

JettyWebFragmentHelper.java

    /**
     *  Manually load <code>web-fragment.xml</code> from JARs and class folders on the classpath.
     * 
     *  <p>Jetty can only find them automatically if the fragment is in a JAR in <code>WEB-INF/lib/</code>.
     */
    protected void loadWebFragments(WebAppContext ctx) {
        Map<Resource, Resource> frags = getOrCreateFragmentResources(ctx);
        try {
            ArrayList<URL> urls = Collections.list(getClass().getClassLoader().getResources("META-INF/web-fragment.xml"));
            urls.forEach(url -> {
                log.debug("Found {}", url);
                Resource value = Resource.newResource(url);
                Resource key = stripJarFile(url);
                
                frags.put(key, value);
                ctx.getMetaData().addWebInfJar(key);
            });
        } catch (IOException e) {
            throw new RuntimeIOException("Error locating web fragments", e);
        }
    }

    public Resource stripJarFile(URL url) {
        String path = url.toExternalForm();
        if (path.startsWith("jar:")) {
            path = StringUtils.substringBefore(path, "!/");
            path = StringUtils.removeStart(path, "jar:");
            return newResource(path);
        } else if (path.startsWith("file:")) {
            path = StringUtils.substringBefore(path, "/META-INF");
            return newResource(path);
        }
        
        throw new IllegalArgumentException("Unsupported URL: " + path);
    }
    
    protected Resource newResource(String path) {
        Resource key;
        try {
            key = Resource.newResource(path);
        } catch (MalformedURLException e) {
            throw new ShouldNotHappenException("Unable to convert [" + path + "] to Resource", e);
        }
        return key;
    }

    protected Map<Resource, Resource> getOrCreateFragmentResources(WebAppContext ctx) {
        @SuppressWarnings("unchecked")
        Map<Resource, Resource> frags = (Map<Resource, Resource>) ctx.getAttribute(FragmentConfiguration.FRAGMENT_RESOURCES);
        if (frags == null) {
            frags = new HashMap<>();
            ctx.setAttribute(FragmentConfiguration.FRAGMENT_RESOURCES, frags);
        }
        return frags;
    }